The tread band of a tire has two circumferential portions, a central one and an inner intermediate one, respectively, that are subdivided into center and intermediate blocks respectively; an inner-shoulder circumferential portion has first and second inner-shoulder cuts, axially offset from each other and distributed in an alternated sequence, to confine a continuous inner-shoulder rest surface with an undulated course; and an outer intermediate circumferential portion has first and second intermediate cuts, and an outer-shoulder circumferential portion has first and second outer-shoulder cuts. The first and second intermediate cuts and the outer-shoulder cuts, respectively, mutually converge at an angle of about 20° and are axially offset from each other and circumferentially distributed in an alternated sequence, to delimit continuous rest surfaces, an intermediate and outer-shoulder surface respectively, with an undulated course.